(1) Field of the Invention
The present invention relates generally to devices that provide aid to persons while they are walking and is especially geared towards assisting persons who have difficulty achieving foot clearance during the swing phase of their gait cycle.
(2) Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
A remarkable number of devices have been proposed as aids to walking and or exercise. Some examples can be found in U.S. Pat. Nos. 420,178; 420,179; 1,608,032; 2,097,376; 3,295,517; 4,329,982; 4,566,447; 5,112,296; 5,186,701; 5,308,305; 5,362,295; 5,372,565; 5,865,203; and 6,361,517. It appears, however, that none of the devices disclosed in these patents is intended to provide or capable of providing assistance to a person in lifting his leg during the swing phase of that person's gait cycle.
A substantial number of persons fail to lift their legs enough during the swing phase of the gait cycle. This is a dangerous deficiency because it makes those people prone to tripping or stumbling over even the smallest obstacles. The problem is most risky for elderly persons who are at a higher risk than the general population for broken bones and, in particular, broken hips and the like.
U.S. Pat. No. 6,361,517 (“Slinger”) discloses a foot lift assist device for enabling a person with drop foot to walk in a nearly normal manner. The Slinger device includes a foot strap that is worn on the toot generally over the toes of the foot. One end of an elastic cord is connected to a ring on the foot strap that is located outside of the centerline of the foot while the other end of the elastic cord is connected or anchored at the person's hip, for example, to a belt. According to the Slinger patent, when a person removes his weight from the foot that has the device attached, the elastic cord exerts an upward force that bends the leg at the knee and hip and exerts an upward force that also pivots the foot upwardly about the ankle. It is noted, however, that when a user's leg is straight, the force exerted by the elastic cord, rather than exerting a force that bends the leg at the knee, it exerts a force that tends to lock the knee and hold the leg straight. It is only after a user of the Slinger device has bent his knee substantially, against the force exerted by the elastic cord, that the elastic cord becomes operable to exert a force that tends to bend the leg at the knee and the hip.